SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccd623a5de80e80dea9e1811a0ec668d99e14a746e74fbeb5c316e7550c6511e' 
  AND token = 'iRLpPTiwd8wLctUSR1p61kTEjH/Kp5E8rexJE3mrU3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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