SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a6d6bd3de8f3b287915c4bdd2d719428156cfb3a90b2815b551d796096877d1c' 
  AND token = 'sNJ2mx5oSKILXK707/qQ7T+ueV3YB1q/+zHvBpw59DQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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