SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44d1f68a13f143285add5d693a8683fa59ab45cae426d784845b0e8668476a49' 
  AND token = 'HzCiBCIprzJb2VkSPXug7u7AkvLxfjIqr87JNpo+Rvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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