SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e87eff7b10ff50a275b405d4af2ace1f396b15b6f069894f361048b43e6f67aa' 
  AND token = 'hOnYXD0x+fjVT2KiiA2nzXYGeQ12jqaGCW+o+LXT3Tw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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