SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a3f923e61cbdc77b57e678a70f8eeef9206b8181f811c09bfea2e5cf1dd1470' 
  AND token = 'Z+zpDY32WkKaVbI3ejSFtx6NLPq0P/AhM+nE3GaNirw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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