SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '929ccb02fb4b92dc5fdff9d2e16d4e78d9cd0dd144ae1863982d3b7ec196b106' 
  AND token = 'oqCbds1lVDW5aYdvHKlCxdx9SqIL5xX6s6sSC4uVcgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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