SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8805c68c8cfebadf51dfdb0b8fb32fd5ee507af865ebfcdb372adfbbbd1e6fb' 
  AND token = 'wk20nFoB3++oTEHc+hwOIJUgU3oKdMq10hD9WaZ3Rms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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