SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '528d31014f848a08cde93f0b999889c9b78c753794f272f7bff031a7ac3c8808' 
  AND token = 'GJgOjSBt70rP73qJUWXB4FkbweGYPPsLOu4+eN7nRms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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