SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acd52368eac06bea7095ae72f46423cf7b1b91cf44bd0759640126ceecff1c11' 
  AND token = 'sTttmebVyuuX2Bs01hxT8V1dOuI4bi5pGfBWaCpJquc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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