SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fe29a2eb6316ab6148d54928577d73de55f254f1258e0b98f1c57906d76ba39' 
  AND token = 'rjDGNJ5O8LO6oMPs5FwB9JY3GMjWvmPBpXCDAGsZJms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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