SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e892fbf09518f9285242827c10f8d73e87d592298c1f2a4641e526a4197c1765' 
  AND token = '8iyyslVFqtVxi/7NkkPGEeBIonhF+6we8PcTvH7GCcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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