SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2aab950d5e5209cacd86d731a1501344752fdb48d3adbe286fefebce613ccdc' 
  AND token = 'c7+B9ZNejyBFDtdHQ9qVzxmhrEMBJJO5mkbX+jWMEh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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