SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3cc28f3dfb347364a6450384e9226aae9bb8ead1cbd26fc27ae9c75c13b627fb' 
  AND token = 'dmps4lVrxnnpf7IYK1p70aeTVE34MCF1x1+zL47+xl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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