SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3b5f3aa61b436a35383d00e4e0f31dd0927ca58e04632a61f0d9418a9b48ec2' 
  AND token = 'hkweS3ByknGO2UeJ/oaKbUWgh1wwAAco1qAAEdEdtxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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