SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f4d2d3346711941d47579b3515c8f1802f84065a7caf09273edc10de6199f020' 
  AND token = 'aSICJiZTzt5w5/OWHuWpBn4R+Aj1+adCINI1NzAXpL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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