SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'aa61e2cb8838e23cd40219ddd994c4d2bdfd0b60464c7306a64e75b5bd422a45' 
  AND token = 'F3Rm7Ta5Y7XZUDrrp2S89VfUm+ukhEy3OFcds9Svalc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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