SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ff2c8588cc00c1bc503ff505691cc8a8a995f16d1a62a48ffa9fabcab50ddd9b' 
  AND token = 'Piws4xtAa7JQuVzZN8x1fG2KHK32ft9iD8DnVjbVAdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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