SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97c523f10b936c0ff16cf735d7e97b7bc9c9791fbd2dc8e089982c9de7c57c10' 
  AND token = 'kGpnFkPxv+6XUgFRNTnUcmpUDQyMV9g/LKcizR23NHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}