SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd691fcd3ea623b1521299d4bf3cd23099a8eee30137fe0e6f797d791fefa6c8' 
  AND token = 'qstQ7Ot+Q1kBMSD/QvWRqNK5l7jW7qQqzlZ4xOKztR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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