SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b0a355d7a539f5d4d91b5daa14e6d26f1602d2f14b475639837fa6d36b440e23' 
  AND token = 'Ah5+yFrWh0FSDoih+87Jitg7xiaKR9UxYHuQurvzh7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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