SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8fc27a8eb3df554cc9ab76dc62840608f66652e420db131c80aa0f880750e15' 
  AND token = 'Sx4tG5nAHt56GoOzhTpVQ+Hfp/UKGwKxi/zPALTaqLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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