SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '199da6935ed6e5c685ad8bd61cea0e91d402654bdbd1e50c79bb288a0eda9339' 
  AND token = 'xchXD5IJSD5qiMIZTRKSBjU7Q5zmtkXRccRFdj3/ygc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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