SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad12a6b5b9677f825df2c7ce1278b2c2df05306ea3853356a4f0afe3266f5f92' 
  AND token = 'BZSkPeChlgfsBE7HmjQmc/SE9QRuCZctbU8l/BFtVVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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