SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0924a922f2093ebfb26aebbc4c1638084eab4812428395d571ae0fec34f1f79' 
  AND token = 'bskiSfxRzcx2JrEZVYYQX/vo8xx362jUh0gceZzw7SU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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