SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f43350211e07ce1850524e3913f13aae6615dfbe8aa46843172a90b22cef847f' 
  AND token = 'iiItqIo1i6ZEgr9L9ZK9gFaDbTCAulw1ImjufL1EG9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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