SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6542766bc865bd0ff41fd130ffd12d5b7ee9344743ebb0f0a4745acbbc1a53c8' 
  AND token = '9W4wAvKCl1oVe1YXDQrl2gt4RY80xP3FlSUtCWv84hI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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