SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0856a5d74497d631deb037938d88e27d87f2dcc37b9aeae15b2ffd308105b142' 
  AND token = 'z7uNxpvJKh8HIGgWTyHLPQ29O4vjyaz1oJfyGvPsNLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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