SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd2b827bd0e83eedabfda7c776554c43781c22b561dcddd1915f4bc3717bc7c89' 
  AND token = '/LmND9jij9qSA8LB2PDzvIoT8/+6y/RG5Ie3YnhexYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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