SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '582a5b477366a21180dd728bcebd6b2baebb2a056d943e319f789501d5f627e5' 
  AND token = 'ng3PzC6OXSRPb2N4tpjYf5sAsy4fgejh15lbUfKlJaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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