SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '649527ba9c8312ad7923a1b5c5d5fc51efc6e9054c5a8a3956b31c926891b0f4' 
  AND token = 'YzOZ6hkTdEstZgmjCzW4tPW4kifJpQRJ9Yh4umvhpVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}