SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '988fcc47b45d235a472574413b21a3e5ade965632967a78b5b7cbbf7870cee94' 
  AND token = 'gzSK6j6RhT/sFRBe7i8F5yyQwK/r5BGA6dx3Ymh0xHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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