SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f672ab1121492762652d94881d93e76fa47abc016c36ac3b59d04d2518a5adc' 
  AND token = 'nDAkW34dri3VVAvlaqtzCJkPjXj56tyCtKwLI4CCvqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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