SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e03723607bc314194e3673c398af1d918a89bde0a26edb5765911b41ff39f45a' 
  AND token = 'lGEPc9wEg4h7EJ6lvuhYeN/L4naBYhi7U7liqu23jUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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