SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '084d2820102ff342b2f0773f1ab3500ed490278c3d0b3bc0016a5377f1e27f6a' 
  AND token = 'WTuD/3eQhjUK/RXsr6ufqlkmA0GdCcILgiKjvcxE+Ac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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