SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71319592d01afd7641e18409bb459ddad5f07ea6814f016172dc51e9e70411e9' 
  AND token = 'bolG6IObtAgn2oMjdSO5hvuDTgSeZRU7IdwWn1w/p0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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