SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '86768ee259c08cc4f2d763c156c7c85969434125417f39fdd2696d3f84c7bc19' 
  AND token = 'RjbqAafR3hV/4EYG8xhLReg3kJ51t45C0PoAUUs+2Y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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