SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ae8b44269f59d845890491359103191048d154340d6d872b3d865cc3ecfc5b1' 
  AND token = 'eq8nz+Z2jskhlDq/g6qcGFOGayml3fG+ZGnC4qjmjFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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