SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '87e0733281e49fb3deb0a2a74c49044968a0e4bc3d545a58229a62b8db119f2e' 
  AND token = '4mpnFLFYnXGS8uY1pnn4DksdO5VDfjdhrp0DDLhKxhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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