SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b084f631d0b6859d3186710a06a15a9eafa51396e5e757c9a8eb57936732905c' 
  AND token = 'BHqjfi3bEpm7sEQgVbJwpePAf48ZyYA7ipMjrjUUefw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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