SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '668021a463d3042aa3a41f6fd5eb8d878bef19b148634909f1bf1888a14c87ab' 
  AND token = 'A8cp7P+I/AJj8K1HDgDwU59vMmZFuu+Ij/fxkzHapCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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