SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19b3650cc5c7afd44fb657cc2533a1c699d5b25cbdf316f7cdd3136348ec5102' 
  AND token = 'GmJSQq5Vai+FVdO98UKw68GVAKosnbgE4HH9Bvp6u/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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