SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3feab7d116f480f0da8773f911e622551932e908af3eb50093305e2ef202a44b' 
  AND token = 'S06VYdyGIT1HyZ3n3WwICz9aKPWwBO8Gz00cy5hDTWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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