SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f67a28b515ce26ce0156dcc1bd4d41aeea576102d92caf18370e6c5137245704' 
  AND token = 'sV1NxprjuFfuHuN4iYxXpjzQqssliO1UppTgAwCYFrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00079

JSON explain

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