SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a7a6d2b86de79724fac2eebe3fc7f2560609af65406b0056419b92c5896a5d56' 
  AND token = 'TZ4AhXLhSB66mNTF8wr3Ef5VJHHm/G0m2JgjegDLVPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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