SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd9ee2ff7a27bcd2740d5fce0659de425a38d7d86d4a4a9cf11dfe2cae47753a2' 
  AND token = 'y/9oeWrGdpdJK2uA4VO9q23FBsPvELc5R0lsa9FralE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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