SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '074b251acc1041250faac713bafd75df41f162f951820f645a4e966ab7f2fd0e' 
  AND token = '+oyClYaNRjGYUdwIPARu5NsKapk5w69e0pfRkmtaABM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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