SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ccb79dfb31b437ab784120cde4c280018415dd9d8a0dcb361b7d42816382f67' 
  AND token = 'KqSuPXqE9s0/zAa8aHh2woLmJqVi6Uu0fpn2k4YTqUE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}