SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a1267476e4cd9fc92e3d893995a334fd19c9763d0129aad58e821e715bcb4e6' 
  AND token = 'RZnjVq7LK9a1h6IJYT/Ie+myGGmGbkrUa2OPJJWxtKk=' 
  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"
    }
  }
}