SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14849eadc0af46cb18c67c8cb6433a80a052a2960c5755065be829d12f292aee' 
  AND token = 'xUfixTWzTTK9ehZ2T6eMilcsEcKvJ/iGkbUQ9GXCsF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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