SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f98f3d0335fb8aabd422b1f14ce31ed95aa430e1eb0280924b2b4cfec55accdb' 
  AND token = '12QdFECBobvP964BjoJGLguWiK+6hC8Yhque0lfJaQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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