SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '292a7517db685af74675311a3570a5cfb5cea57b4ce36285bc2a3a7bf01272bb' 
  AND token = 'PypdPbmVnQl23GzIyH1Bt9tsvwVjaASY4jEcwS4CIEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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