SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '645ee63c6f23867d29fa6641f9d267244af7ac53d7460f150bdba82db393377c' 
  AND token = '+QDNXx/6BaSony/a4yKD4wyvbLTJDCvI1qqZ8wAPqlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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