SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd583ede2da4223c19184ebcde1ecc7b65a9a2f84d06b7eb82303dfca3343150' 
  AND token = 'YMFDbHic+ovDcmejQbzS0MOY/MadWql+9FYg/MV+ggY=' 
  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"
    }
  }
}