SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '52b1e7e19bf4880430c9199ee719d902e330151a45ae259f3fdf1c2333fd8cb7' 
  AND token = '5GtxstYL1Qw+oE/rbQeM006zC02LQ9ZOOOr4eJJBF+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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