SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3b7c1ce2fd56a3793eec049ce04781cbeedd80b15a6f2a4b074ad8e1db42100c' 
  AND token = 'vnuQ1qmCrx8EY1E6rRWZ1t43iWKbCjhlLbJ6WUya7Ks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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