SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d23607931846c304087b729a5a1f2885e35bebb1978d880b2a8ab0bf3d4580e' 
  AND token = 'rJPhTz3CrB7PjfidmzKsFU4QlRgLtDKfPEiV7tG2iqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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