SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e60743bf7b323d81a17c341da4c19a19176b9d933fb25c03d718ccbc1b82fda' 
  AND token = 'SNWKAOOry9yRzKboXRofgcqasLdxCJ5YpFI/0WqM+rk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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