SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba627aace66ecc62ace0412df93bb7012927137783ae9169302d9bf14ae24ea4' 
  AND token = 'W38QgeczhCY6kjPhQkGwkaQgtiLKR6ffS8zHtaWyjJQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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