SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd396bc9b80377a30272a162df2ce8e145ea214154f256a0928a213cd85951916' 
  AND token = 'riwgXoccJnVk5Tn4NX5vsfIIiCm+tT4x3GEG47Pi5FA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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