SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db1bd4bf15df2e66401f997dbed0663fb8ea176ed3a1948dee77e1f53606f775' 
  AND token = 'hmD+wbh2p6Aw8GBHkhquPi9WUlovKXcHtjVjBLX4d5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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