SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c424459738c7895af6d788e6d763f0a11294966c9b4f47b20e27cdf52b7b430' 
  AND token = 'eIODJ0YqfBQL9LObGkLqjSg+vgmGu+4IX9GvJn107+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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